In providing clothing, such as gloves and boots, for example, which is effective for protecting the wearer against hazardous materials, it is often difficult to protect against more than one particular class of hazardous material. For example, protective wear designed to protect against chemical warfare agents and/or toxological agents such as nerve gases and mustard gas, are normally made out of a butyl rubber such as isobutylene-isoprene (IIR) which may be a copolymer of isobutylene and isoprene typically having 1-5% of the diene monomer. The butyl rubber provides favorable impermeation protection against a wide variety of both chemical and biological warfare agents while providing excellent properties such as tensile strength, modulus of elasticity, tear resistance, low temperature flexibility and resistance to decontaminating agents and the latest U.S. Military specifications for protective clothing requires the use of butyl rubber as a base polymer. Further, the cost of alternatives to butyl rubbers is prohibitive.
However, problems arise in using butyl rubber based protective wear especially when the protective wear is exposed to hydrocarbons such as those found in fuels, oils and lubricants. The butyl rubber based protective wear, when subjected to such hydrocarbons, exhibits a drastic increase in volume as well as in weight. Properties such as tensile strength, modulus of elasticity, elongation at break, and abrasion resistance are drastically impaired. Consequently, also adversely affected is the article's impermeability which results in ineffective protection. An especially undesirable situation results when a butyl rubber based protective article has been exposed to such hydrocarbons in the presence of a hazardous material, such as strong oxidizers, including inhibited red fuming nitric acid (IRFNA) and hydrazine, both used as rocket fuels. In such a case, the article's integrity may be compromised by the hydrocarbon and the hazardous material may permeate through the article and contact a wearer.
A further problem with protective wear using sulfur-crosslinked butyl rubber as a base polymer is encountered in environments having elevated temperatures as the protective wear breaks down. More specifically, crosslinks in the butyl rubber provided by sulphur or sulphur bearing materials to strengthen the article are relatively unstable at elevated temperatures and tend to revert or, in other words, break due to the elevated temperature; and this adversely affects the efficacy of the protective wear.
The present invention is directed toward overcoming one or more of the problems as set forth above.